William e



(No Model.)

W. R. COLE.

TELEPHONE TRANSMITTER.

Patented Oct. 19, 1886.

NITED STATES PATENT OFFICE.

WILLIAM R. COLE, OF DETROIT, MICHIGAN, ASSIGNOR TO HIMSELF, FRANK G. SMITH, AND GEORGE \V. MOORE, TRUSTEES, ALL OF SAME PLACE.

TELEPHONE-TRANSMITTER.

SPECIFICATION forming part of Letters Patent No. 351,250, dated October 19, 1886.

Application filed March 3, 1865. Serial No. 157,689. (So model.)

To all whom it may concern.-

Be it known that 1, WILLIAM R. COLE, of Detroit, county of Vayne, and State of Michigan, have invented a new and useful Improvement in Microphone-Transmitters5 and I do declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawings, which form a part of this specification.

The nature of this invention relates to certain new and useful improvementsin telephonetransmitters, the object of which is to give a strong undulatory current without any break in the connection, so that the articulation may 1 be clear and distinct, and to obviate the frying and metallic sounds produced in transmitters where the connection is not absolutely maintained.

Figure 1 is a longitudinal section on line arm of Fig. 2, showing the Various parts. Fig.2

is a perspective view of the same.

In the accompanying drawings, which form a part 01' this specification, A represents a metal diaphragm; B, a rubber ring upon which the diaphragm rests.

O is a wooden. base on which the rubber ring is held.

D is a mouth-piece. c e are clamps for holding the diaphragm in its place.

F is a polarized magnet hung on trunnions g, which trunnions are pivoted between lugs of yoke h, which bridges over the diaphragm and is securely fastened to the base 0, leaving 5 a space, so that it does not interfere with the vibrations of the diaphragm.

I is a platina point secured to the center of the diaphragm,

J is a carbon button.

K is a brass or other unmagnetizable metal screw that forms a socket for holding the carbon button, and is also used for adjusting the same.

L is an adjusting screw of unmagnetizable metal, to prevent the magnet from tipping for- 5 ward and engaging the diaphragma In operation the carbon button is adjusted to'allow the magnet to attract toward the center of the diaphragm until the required amount of pressure is brought to bear upon the platinum point. The smallscrew L is then adjusted so as not to interfere with the vibrations, but so as to prevent the magnet from changing its position under heavy vibrations. The carbon button never leaves the platinum point, thus preventing oxidization, and the articulations are clear and distinct. The vibrations of the diaphragm upon the carbon button increase or decrease the attraction of the magnet at either end, thus varying the undulatory currents as required.

hat I claim as my invention is 1. In a telephone-transmitter, the combination, with the diaphragm, a yoke bridging the same, trunnions pivotally supported by said yoke, and a permanent magnet supported by said trunnions, of a carbon, and screws for adjusting the pressure of the carbon upon the diaphragm, substantially as described.

2. In a telephone transmitter, the combina tion, with the ring 0, rubber ring 13, diaphragm A on said ring B, and clamps holding said ring and diaphragm to the ring 0, of the yokebridging said diaphragm and provided with lugs l2, trunnions g, journaled in said lugs, magnet F, supported by said trunnions, carbon J, and adjusting-screws K L, all substantially as and for the purposes specified.

\VILLIAM R. COLE.

XVitnesses:

H. It. RANKIN, M. llICNAMARA. 

